Lose all power? Are we talking electric or the engine's ability to move the car?

The trany not shifting may be a sign of transmission issues or it may be related to "limp mode" where the computer holds it there when other systems are not right.

I suspect the brake lights are not related. I'd check to be sure the bulbs are good before jumping into the hard stuff. Several burned out bulbs is a common situation.

Back to the running / trany issues, I'd get a computer scan and post the codes here so we have some hints of what might be the root cause. Also have the codes cleared so anything that retuurns is current and not old history.